SWAMPy

✎ CARVE FLESH

EDITING: index.js

/*
 * Copyright (C) 2019 - present Instructure, Inc.
 *
 * This file is part of Canvas.
 *
 * Canvas is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, version 3 of the License.
 *
 * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */
import {addMockFunctionsToSchema, makeExecutableSchema} from 'graphql-tools'
import {addTypenameToDocument} from 'apollo-utilities'
import {graphql} from 'graphql'
import gql from 'graphql-tag'
import {mergeWith} from 'lodash'
import {print} from 'graphql/language/printer'

// If file is not present locally, run `bundle exec rails graphql:schema`. This
// file is generated automatically on a jenkins run
import schemaString from '../../../schema.graphql'

// Mock our custom scalar values in the canvas graphql schema
const DEFAULT_MOCKS = [{URL: 'http://graphql-mocked-url.com'}, {DateTime: null}]

// Allow you to merge and replace an existing array with an empty array.
// https://github.com/lodash/lodash/issues/1313
function emptyArrayReplaceCustomizer(obj, src) {
  if (Array.isArray(src)) {
    return src
  }
  return undefined
}

// Get and cache the valid types that can be mocked
let _typeIntrospectionSet = null
async function getValidTypes() {
  if (_typeIntrospectionSet !== null) {
    return _typeIntrospectionSet
  }

const typeIntrospectionQuery = '{ __schema { types { name } } }'
  const schema = makeExecutableSchema({
    typeDefs: schemaString,
    resolverValidationOptions: {
      requireResolversForResolveType: false,
    },
  })
  const result = await graphql(schema, typeIntrospectionQuery)
  _typeIntrospectionSet = new Set(result.data.__schema.types.map(type => type.name))
  return _typeIntrospectionSet
}

async function createMocks(overrides = []) {
  const mocks = {}
  if (!Array.isArray(overrides)) {
    overrides = [overrides]
  }

const validTypes = await getValidTypes()
  const allOverrides = [...DEFAULT_MOCKS, ...overrides]

allOverrides.forEach(overrideObj => {
    if (typeof overrideObj !== 'object') {
      throw new Error(`overrides must be an object, not ${typeof overrideObj}`)
    }

Object.keys(overrideObj).forEach(key => {
      // Sanity check. If someone tries to add an override that doesn't exist in
      // the schema, we are going to fail hard here instead of having unexpected
      // results returned from this function
      if (!validTypes.has(key)) {
        const err =
          `The override "${key}" is not a valid graphql type. ` +
          'Did you typo it or forget to update your graphql schema? ' +
          '`bundle exec rails graphql:schema`'
        throw new Error(err)
      }

const defaultFunction = mocks[key] || (() => undefined)
      const defaultValues = defaultFunction()
      const overrideFunction =
        typeof overrideObj[key] === 'function' ? overrideObj[key] : () => overrideObj[key]
      const overrideValues = overrideFunction()

// This if statement handles scalar types. For example, saying that all URL
      // types resolve to a dummy url, regardless of where they show up in the query
      if (typeof overrideValues !== 'object' || overrideValues === null) {
        mocks[key] = () => overrideValues
      } else {
        mocks[key] = () => mergeWith(defaultValues, overrideValues, emptyArrayReplaceCustomizer)
      }
    })
  })

return mocks
}

function nodeInterfaceProperlyMocked(queryAST, mocks) {
  // flatMap
  const selections = queryAST.definitions.reduce(
    (acc, d) => acc.concat(d.selectionSet.selections),
    []
  )
  const selectionNames = new Set(selections.map(s => s.name.value))
  if (selectionNames.has('node') || selectionNames.has('legacyNode')) {
    return !!mocks.Node?.()?.__typename
  } else {
    return true
  }
}

export default async function mockGraphqlQuery(query, overrides = [], variables = {}) {
  const queryAST = typeof query === 'string' ? gql(query) : query
  const mocks = await createMocks(overrides)

// Catch common mistake of forgetting to override the __typename for node interface
  if (!nodeInterfaceProperlyMocked(queryAST, mocks)) {
    const err =
      'You must add a __typename override to tell the node interface what type ' +
      'you are expecting. For example: `{Node: {__typename: "Course"}}`'
    throw new Error(err)
  }

// Turn the AST query into a string that can be used to make a query against graphql.js
  const queryStr = print(addTypenameToDocument(queryAST))
  const schema = makeExecutableSchema({
    typeDefs: schemaString,
    resolverValidationOptions: {
      requireResolversForResolveType: false,
    },
  })

// Run our query againsted the mocked server
  addMockFunctionsToSchema({schema, mocks})
  const result = await graphql(schema, queryStr, null, null, variables)
  if (result.errors) {
    const errors = result.errors.map(e => e.message)
    throw new Error('The graphql query contained errors:\n  - ' + errors.join('\n  - '))
  }
  return result
}

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📁 __tests__/	DIR	—	2023-09-24 03:36
📄 index.js	JS	5.3 KB	2023-09-24 03:36	EDIT
📄 package.json	JSON	126 B	2023-09-24 03:36	EDIT
📄 README.md	MD	7.5 KB	2023-09-24 03:36	EDIT